Hi,
Just to add my experience here.
- For those starting from Poroy station, even from the Plaza Armas, i think it will take about 20-30 mins max to arrive at the station. From the HGI, it took me about 15 mins. There is really no need to arrive max 30 mins before as there is not much to do and when the doors open to the train, you have to go to your own carriage for check in.
- After arriving at Aqua Calientes station, it was not too bad from people crowd point of view. The only main complain is the direction to the location to get the bus tickets, After the direction sign at the station, there was none again, after going in some rounds, saw the buses, BUT that is NOT the place to get your tickets, you have to walk in the opposite direction (~ 5 mins) to a small (hidden) office to get your tickets (which cost ~USD 24 pp return).
- Luckily the line was short and wait was less than 5 mins before boarding the bus. Ride up to the entrance was about 15 mins.
- At the entrance, guide service is offered and there is NO need to employ them if not needed. You can enter without any guide.
- After entering, just follow Route 1 (Circuit 1) and it should be ok. There is a 2nd route option which leads you directly into the village. I would suggest just follow Circuit 1 and it should be ok.
- I spend in total about 3 hours around the whole site, but if you are with a guide, this will be more than that. You can stay in the area even after your time is over (as mentioned by Astrophsx).
- For the return journey, the line was quite long, but they started more buses up so wait was only about 15 mins before I could get on the bus.
- For those ending at Ollantaytambo station and you need to get back to Cusco (cheaply), after leaving the station just walk about 100m further and around the arch, you can get Collectivos back to Cusco for ~10 PEN, which for those staying at HGI, it will drop you off close to the cathedral (Santa Ana area) and you just walk back to the hotel - very convenient.
Hope the above helps those travelling soon and staying at the HGI. I was lucky as the weather was sunny and (hot!) during my time up there.
Cheers!